Fuel tank closure device

ABSTRACT

A fuel tank closure device includes a base sized to be received within an interior of fuel tank filler neck, a closure structure movably mounted on the base, and a biasing mechanism secured to the base and biasing the closure structure into a closed position on the base.

This application claims the benefit of U.S. provisional patent application Ser. No. 61/206,489, filed Jan. 30, 2009.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a fuel tank closure device and method, and in particular, to a fuel tank flapper door, to reduce the fuel and/or fumes that may exit a fuel tank when a fuel cap is not positioned on a fuel tank opening.

2. Background of the Invention

Fuel tanks may include a cap removably secured to a fuel tank opening to seal the opening of the fuel tank during use of the vehicle to which the cap is attached. However, in some instances the cap may not be installed after a fuel fill up or may be improperly installed and fall from the fuel tank opening during use. In such situations, fuel and/or fumes may exit the fuel tank through the fuel tank opening. It may be desirable to reduce the fuel and/or fumes that may exit the fuel tank opening when the cap is not positioned thereon.

OBJECTS OF THE INVENTION

It is an object of this invention to provide a fuel tank closure device and method that reduces fuel and/or fumes that are released from a fuel tank when a cap is not positioned on the fuel tank opening.

SUMMARY OF THE INVENTION

The present invention provides a fuel tank closure device, namely, a biased door assembly, that may be installed within the neck of a fuel tank filler assembly. In a nominal position the door may be biased into an closed position so as to seal the fuel tank filler neck and thereby reduce fuel and/or fumes that may exit through the fuel tank filler assembly when a cap is not sealingly positioned thereon. The door may be moved to an open position by placement of a fuel pump nozzle downwardly within the fuel tank filler neck, so that fuel may be pumped into the fuel tank through the fuel tank filler neck, without hindrance by the door assembly. After removal of the fuel pump nozzle, the door is biased back into the closed position to seal the fuel tank filler neck.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side cross sectional view of a fuel tank closure device installed in a fuel tank filler neck, the section taken along section line 1-1 of FIG. 2.

FIG. 2 is a bottom cross sectional view of a fuel tank closure device installed in a fuel tank filler neck, the section taken along section line 2-2 of FIG. 1.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1 is a side cross sectional view of a fuel tank closure device assembly 10, also referred to as a fuel tank flapper door assembly 10, installed in an anti-siphon device 12, that is installed a fuel filler neck 14. Fuel filler neck 14 may be installed in a fuel tank (not shown) so as to allow a fuel pump nozzle (not shown) to be inserted therein for filling the tank with fuel. Anti-siphon device 12 may be installed within fuel filler neck 14 to reduce or prohibit undesirable siphoning of fuel from the fuel tank. Fuel tank flapper door assembly 10 may be installed within anti-siphon device 12 or directly into fuel filler neck 14.

Flapper door assembly 10 may include a cylindrical base 16 including an exterior circumferential groove 18 that may receive therein a protrusion 20 extending outwardly from an inner wall 22 of anti-siphon device 12, to secure assembly 10 in place within anti-siphon device 12, and thereby to secure assembly 10 in place within fuel filler neck 14. Groove 18 may be positioned perpendicular to an elongate axis 19 of base 16. In one embodiment, protrusion 20 (and groove 18) may extend around a portion of a circumference of the inner wall 22 of anti-siphon device 12, around several portions of the inner wall 22 of device 12, or completely around the inner wall 22 of anti-siphon device 12. In other embodiments, flapper door assembly 10 may be secured to the inner wall 22 of an anti-siphon device 12 or the inner wall 24 of a fuel filler neck 14 by any available means such as set screws, inwardly extending tabs, welding, threads, adhesive, or the like.

Base 16 of assembly 10 may include secured thereto a hinge mechanism 26 that may include a biasing device 28, such as a spring, so that a door 30, secured on base 16 by a pin 31, is biased into sealing engagement with an O-ring 32 on cylindrical base 16. A force of spring 28 may be overcome by the downward force of a fuel pump nozzle (not shown) on door 30 when such a nozzle is inserted through an opening 34 of fuel filler neck 14, through an opening 36 of anti-siphon device 12, and through an opening 38 of cylindrical base 16 such that the fuel tank may be filled with fuel. Door 30 may include a domed region 40 in a central portion thereof to strengthen the door 30 and to increase the sealing properties of the door 30 against O-ring 32. Domed region 40 may extend upwardly into opening 38 of base 16.

Once the fuel pump nozzle is removed, spring 28 may bias door 30 to move into sealing engagement with O-ring 32 on cylindrical base 16. In this manner, fuel and/or fumes may be hindered from exiting the fuel tank even when a fuel cap (not shown) is not installed on, or has fallen from, the fuel filler neck 14. An air tight seal between anti-siphon device 12, or fuel filler neck 14, and cylindrical base 16 may be enhanced by use of a second O-ring (not shown) which may be positioned within a circumferential groove of cylindrical base 16 so that such an O-ring would be positioned between base 16 and inner wall 22 of anti-siphon device 12.

Still referring to FIG. 1, door 30 is shown in an open and lowered position by dash lines 42 when a fuel pump nozzle (not shown) is placed within filler neck 14. The spring 28 in the open position is shown as dash lines 44. After removal of the fuel pump nozzle (not shown), spring 28 biases door 30 back into the closed and raised position (shown in solid lines) so as to seal fuel filler neck 14 against the escape of fuel and/or fumes from the fuel tank to which the fuel filler neck 14 is secured.

In one embodiment, base 16 and door 30 may be manufactured of a generally rigid plastic, and pin 31 and biasing device 28 may be manufactured of metal. In particular, base 16 may be manufactured of a material that may be press fit into the interior of anti-siphon device 12 such that the base 16 may be pressed downwardly over protrusion 20 positioned on inner wall 22 of anti-siphon device 12 until protrusion 20 is received within groove 18 of base 16 so as to secure base 16 within anti-siphon device 12. However, any materials suitable for a particular application may be utilized in the device 10 of the present invention.

A method of sealing a fuel filler neck assembly will now be described. The method includes securing a base 16 within a fuel filler neck assembly 14, the base defining an opening 38 for the passage of fuel therethrough. The method also includes movably securing a closure structure 30 on the base 16, the closure structure 30 movable between a closed position wherein the closure structure seals the opening 38 and an open position wherein the closure structure 30 is moved out of position from the opening 38, thereby allowing the passage of fuel through the opening. The method also includes securing a biasing structure 28 on the base 16, the biasing structure 28 biasing the closure structure 30 into the closed position in a nominal condition, i.e., in the absence of an external force on closure structure 30.

FIG. 2 is a bottom cross sectional view of a fuel tank flapper door assembly 10 showing door 30 in a nominal closed and raised position.

Other variations and modifications of the concepts described herein may be utilized and fall within the scope of the claims below. 

1. A fuel tank closure device, comprising: a base sized to be received within an interior of fuel tank filler neck; a closure structure movably mounted on said base; and a biasing mechanism secured to said base and biasing said closure structure into a closed position on said base.
 2. The device of claim 1 wherein said base is sized to be received completely within said interior of said fuel tank filler neck.
 3. The device of claim 1 wherein said base includes an interior opening sized to allow the passage therethrough of a fuel pump nozzle.
 4. The device of claim 3 wherein said closure structure is movable into an open position on said base wherein said closure structure is moved out of position against said interior opening of said base.
 5. The device of claim 1 wherein said base defines a substantially cylindrical external shape including a curved outer surface.
 6. The device of claim 5 wherein said curved outer surface includes a groove extending circumferentially around at least a portion of said curved outer surface, said groove positioned perpendicular to an elongate axis of said base.
 7. The device of claim 3 wherein said closure structure includes a dome shape that extends upwardly into said interior opening of said base.
 8. The device of claim 1 wherein said base includes a sealing member secured thereto, said sealing member positioned to seal against said closure structure when said closure structure is in said closed position.
 9. The device of claim 1 wherein said closure structure in said closed position seals said fuel tank filler neck against the passage of fuel therethrough.
 10. A fuel tank anti-leak system, comprising: a base that defines a cylindrical outer surface including a groove extending at least partially around a circumference of said cylindrical outer surface and an inner surface that defines an opening sized to allow the passage of a fuel pump nozzle therethrough; a closure structure movably mounted on said base; and a biasing mechanism secured to said base and biasing said closure structure in a nominal condition into a closed position on said base such that said closure structure covers said opening of said base.
 11. The system of claim 10 further comprising a sealing member secured to said base, said sealing member sealingly engaging said closure structure around said opening when said sealing structure is in said closed position.
 12. The device of claim 10 further comprising an anti-siphon structure sized to be positioned within a fuel filler neck, said anti-siphon structure defining an inner surface including a protrusion, said protrusion positioned within said groove of said base to secure said base to said inner surface of said anti-siphon structure.
 13. The device of claim 10 wherein said opening of said base defines a substantially circular opening, and wherein said closure structure defines a substantially circular door having a circumference greater than a circumference of said opening.
 14. The device of claim 10 wherein said closure structure is movable against said biasing mechanism into an open position wherein said opening of said base is unobstructed by said closure structure.
 15. A method of sealing a fuel filler neck assembly, comprising: securing a base within a fuel filler neck assembly, said base defining an opening for the passage of fuel therethrough; movably securing a closure structure on said base, said closure structure movable between a closed position wherein said closure structure seals said opening and an open position wherein said closure structure is moved out of position from said opening thereby allowing the passage of fuel through said opening; and securing a biasing structure on said base, said biasing structure biasing said closure structure into said closed position in a nominal condition.
 16. The method of claim 15 wherein said biasing structure biases said closure structure into said closed position in the absence of an external force on said closure structure that is greater than a biasing strength of said biasing structure.
 17. The method of claim 15 further comprising securing a sealing member to said base around said opening, said closure structure sealingly engaging said sealing member when said closure structure is in said closed position.
 18. The method of claim 15 wherein said securing comprises securing a groove of said base on a protrusion of a fuel filler neck assembly.
 19. The method of claim 18 wherein said fuel filler neck assembly is chosen from one of a fuel tank filler neck and a fuel anti-siphon assembly secured within a fuel tank filler neck.
 20. The method of claim 15 wherein said closure structure comprises a door including a dome extending upwardly into said opening when said door is in said closed position. 